Sylvinite flotation with amine composition



United States Patent 3,310,170 SYLVINITE FLOTATION WITH AMINECOMPOSHTHON Charles W. Abernathy and Milton H. Klein, Carlsbad,

N. Mex., assignors to American Metal Climax, Inc.,

New York, N.Y., a corporation of New York No Drawing. Filed May 18,1964, Ser. No. 368,405

9 Claims. (Cl. 209166) This invention relates to the beneficiation ofsylvinite ores to produce concentrated sylvite values. Moreparticularly, the present invention relates to the concentration ofsylvite values from sylvinite ores by froth flotation employing improvedcationic sylvite collecting reagents.

It has, of course, been known heretofore to employ froth flotationreagents to effect the concentration of desired mineral values. Morespecifically, it has been known to employ aliphatic fatty acid aminesalts, and, illustratively, primary aliphatic amine salts wherein thehydrocarbon moieties contain at least eight carbon atoms, as sylvitecollectors.

It has also been suggested hitherto to enhance the effectiveness offatty acid amine collector salts by increasing or decreasing the degreeof unsaturation in concert with the temperature of the brine solute inwhich the pulp is suspended. This procedure, however, involves obviousdisadvantages inherent in correlating hydrogenation of the hydrocarbonportions of the amines involved with the consistently varyingtemperatures which normally occur in the environments wherein thesefroth flotation procedures are performed. To control the temperature ofthis environment would, on the other hand, be unduly costly.

It has now been discovered, however, that a unique and selective mixtureof primary saturated (mostly) amine salts may be had which will providea significantly improved and efficient sylvite collecting reagent atambient temperatures. Accordingly, the present invention is based on thediscovery that a pulp formed from comminuted sylvinite ore suspended ina brine saturated with the constituents of said ore is most effectivelyconditioned for froth flotation at ambient temperatures by introductiontherein of a cationic mineral collector composition composed of 60percent to 80 percent, and desirably 65 percent to 75 percent, of theacid addition salts of hydrogenated tallow amine and 40 percent topercent, and preferably percent to 25 percent, respectively, of cocoaamine salt and most desirably one formed from 75 percent of hydrogenatedtallow amine salt and 25 percent of cocoa amine salt, having an iodinevalue preferably below 12.

The foregoing preferred cationic amine composition (i.e. a mixture ofabout 75 percent hydrogenated tallow amine salt and 25 percent cocoaamine salt) contains the primary normal or unbranched saturated andolefinically slightly unsaturated aliphatic fatty acid amines havingfrom 8 to 18 carbon atoms in the approximate percentages by weightindicated in Table I.

The foregoing amines are, as indicated, employed in the form of theircorresponding acid addition salts prepared in the usual manner byreaction of the amines with suitable acids such as sulfuric acid,phosphoric acid,

the hydrohalic acids, e.g. hydrobromic acid and hydrochloric acid, oracetic acid. In this manner the amine collecting reagents of theinvention are rendered watersoluble.

The effectiveness of the flotation step is influenced significantly bythe chain lengths of the hydrocarbon, i.e. alkyl and alkenyl, radicalspresent in the hydrogenated tallow amine and cocoa amine salts, and therelative proportions of the various chain lengths within the rangerecited, i.e. 8 to 18 carbon atoms, when inter-related with the primarysaturation of the components. Although not narrowly critical, thepreferred concentration of cationic collector per ton of the comminutedore feed is .07 pound to .16 pound. The preferred particle sizes ofcomminuted ore to which the instant amine reagents are applied are ofminus 8 mesh.

The nonmetallic mineral ores subject to the practice of the presentinvention are particularly those potash ores containing mixtures ofoceanic salts and clays of which sylvite (potassium chloride) is anormal constituent. A major and illustrative source of sylvite (KCl) inNorth America is the mineral deposits of the Permian Basin, andparticularly those occurring in the vicinity of Carlsbad, N. Mex. Otherknown sources of suitable ore deposits are those present in California,Utah and Saskatchewan, Canada.

The sylvinite ore is characteristically subjected, after being mined, toa preliminary crushing, employing conventional grinding apparatus, andis sequentially comminuted by passage thereof through a hammermill,pebble mill, or by impact pulverization to liberate the sylviteconstituents of the ore. Comminution of the ore is indeed preferablycarried out by impact pul-verization with substantially dry ore. Theresulting mill feed is then, in one illustrative procedure, admixed witha brine solution saturated with the constituents of the sylvinite oreand suspended in the brine to provide a pulp which is then subjected tovarious forms of violent agitation in a scrubbing operation whereinsubstantial quantities of the clay slimes present in the ore arereleased from the salt crystals therein and suspended in the brine whichis then removed. Thereafter the sylvinite pulp is passed to sizing andclassifying apparatus employing such conventional equipment as cyclones,rake and bowl classifiers, wet or dry stationary or vibrating screens,settling cones, hydroseparators, and the like.

In the classifying operation at least two fractions of pulp areprepared; one containing, for example, under-size particles of 65 meshor finer and a second fraction of plus 65 mesh. The former fractioncontaining the undersize or fine particles of sylvite also containsconsiderable quantities of residual slimes which are partially andconveniently removed suspended in brine as overflow fromhydroseparators. The brine of this overflow, which is saturated withsylvinite ore constituents, is normally separated from the foregoingslimes and recycled for use with another portion of mill feed. Theremaining fraction or fractions containing coarser or oversize particlesof comminuted ore are normally combined thereafter with the partiallydeslimed first fraction of undersize ore particles and the resultingpulp is then conditioned for the froth flotation steps to follow.

Conditioning is effected by introduction into the pulp of the aminereagent composition of the present invention as described hereinabove,preferably in the amount and concentration indicated, followed byagitation of the resulting mixture. This agitation is accomplishedeither mechanically or by means of a current of air or other unreactivegas. The cationic conditioning or collecting compositions of theinvention may be introduced into water-immiscible oils, such as pineoil, fuel oil, or kerosene, or with a frothing reagent of commercialgrade, such as methyl isobutyl carbinol, which cooperate with thecationic amine salt flotation reagents of the invention. Flotation oils,where included, are usually not introduced be separately treated withthe conditioning reagents of the invention; or, indeed, a fractioncontaining the coarser particles may be admixed initially, separatelyand solely, with the cationic collectors here involved, subjected to ain excess of .08 pound thereof per ton of mill feed; a 5 rougherflotation separately, and the rougher concentrate desirable range, insuch instances, being from 0.03 to .06 recovered therefrom thensubjected to a cleaner flotation pound per ton of sylvinite mill feed.in admixture with the fine pulp fraction, the amine col- Due to theuneconomic and impractical mechanical lector introduced in the foregoingconditioning step havmethods presently available for eflecting completereing been provided in an amount suflicient to serve moval of clayslimes from the pulp, there is introduced, effectively for collection ofthe sylvite values in both the usually in the conditioning step, priorto conditioning rougher and cleaner flotations and, for that matter, ifdewith the collector, an auxiliary reagent to inhibit the adsired, inany recleaner flotation step to follow. Accordverse effect of theresidual slimes upon the collection, ingly, an illustrative procedurewherein the cationic particularly of the coarser values, In the froth fltation sylvite collecting compositions of the present invention step orsteps. i can be employed is described in copending applicationIllustrative of such inhibiting reagents are starch, Ser. No, 320,388now Patent Number 3,282,418 filed dextrin, the polyglycols and theirethers disclosed in by the applicants herein on October 31, 1963. Patent2,724,499 of Smith et al., and the water-soluble The following examplesare further illustrative of the acrylonitrile polymers of Patent2,919,026 of Smith et al.; invention, that is, by way of furtherillustration, a water-soluble E I 1 acrylonitrile polymer in which atleast one nitrile group xamp 6 has biien modlfied by alcoliolysls toprpduce the Cone Twelve samples of asylvanite ore mined in the Carlsbad,sponding ester and/or alkaline hydrolysis to produce the New Mexicoregion each conmining about 23% K20 corresponding salt. 7

Where the auxiliary reagent is a polygl l or po1y 25 equivalent ofpotassium chloride (see table), are com glycol ester having a molecularweight of at least 300 the -t i g g E a g provi e ami ee. ac o t e mi eesis su ecte quannty of g employed. Is at least pound i individually andsequentially to scrubbing for the pur ton of the ore initially submittedto the process as mill feed. In like manner, where a water-solubleacrylonitrile i g g prehmmigy desh'mmgf tg mirgggctlod o a rine aving aspeci c gravity 0 a out an polymer is utilized as an auxiliary reagent,the concentration thereof is at least 0.02 pound per ton of sylvinitegiz z g g g g fig $5 55 :3333???tg tifg i i mill feed. It will beevident, too, that other standard conditioning 5mg scrubbmg operatlopcontams about 'percent by and Cooperating reagants known heretofore y beweightof suspended solids. The pulp resulting from the ditionallyintroduced, optionally, in known concentraloregonig prehmmary dishml-ngoperatlon. m each mtions in the sylvinite pulp to be subjpcted to frothflotation stance, is thereafter classified into two fractions of about15 percent 65 mesh or finer and 85 percent plus 65 mesh d h $232312?iiith fioiiiii f ifiiit 53 5? aesiabi by standard e s T finer Pulp ofeach Sample accomplished in deep air cells of standard manufacture, ffif f i l particles of 65 mesh or fingr 15 can also be effected in anyof a variety of other means, 40 i ig ss fi zg g gg h z fi g g such asDenver Equipment Company cells, Mineral Sepa- A a r 9 9 p us F an rationcells, Forrester Air-Lift cells, and Turbo-cells, as each.(.)f i.lesultmg composltlolis 18 then subject.ed to well as in laboratorymodels, such as the Fagergren flocondnfnnig In manner pi i i ii fi mtionmachine. concen rations an amounts in icate in a e II. T e In oneillustrative method, the pulp is subjected to a emclenqy 9 thefiotatlonrecovery procedure. 9 plurality or sequence of flotation operations,such, for exthe catlomc amnlvle salt reagent? Indicated 1s ample, as aninitial rougher flotation, a cleaner flotation, also relimsemed m Table.The i and a recleaner flotation, which are standard procedures i f H theformfof a 3 p salts well-known in the art. It will be evident that thefroth C eimca y unreac we W1 e.cons 1 uents t sy flotation techniques,wherein the cationic sylvite collectors Yamte added to the reSPeCtVesamp 16S as uidlcated of the present invention are employed, may bewidely to are r.epreS.enL.ed by the symobls m Table varied. Thus, forexample, the fine fraction containing H havmg the followmg s1 gmficance:ore particles of 65 mesh or finer, and the other fraction distilledtallOW amine hydfochlofidfi or fractions containing particles of plus 65mesh resultdistined y g tauow amine hydrochloride ing from the sizingand classifying means employed, may 53 C. cocoa amine hydrochloride,distilled and saturated TABLE II R t ,Lb Sample Amine Tgn ofMi llPercentKao l r eii r i i N 0. Used Feed K20 Equiv- Feed Concentrate Tailalent (a) A .07 23.45 58.45 6.44 81.52 (b)- 5:: .07 23.19 59.28 3. 5989. 83 (c) g .07 23.30 59. 46 2. 99 91.78 B 07 23. 05 54. 04 6.35 82. 09

The procedure of this example is carried out at ambient temperatures,which in each of the foregoing instances is about 70 F.

Percentages in the foregoing Table II as well as throughout thisspecification refer to percentages by weight unless otherwise explicitlyindicated.

The marked enhancement in efficiency of the flotation recovery in thoseinstances where a mixture of hydrogenated distilled tallow aminehydrochloride and distilled cocoa amine hydrochloride within theproportions of the invention are employed, i.e. with samples (b), (c),(g), (h) and (k), over those instances where a hitherto known flotationreagent, distilled tallow amine hydrochloride, i.e. ore samples (a),(e), (i) and (l); hydro- A distilled tallow amine such as the foregoinghas an iodine value, indicating the degree of unsaturation thereof,normally, within the range of about 40 to 48. Hydrogenated distilledtallow amines used in the form of their acid addition salts manifest, ofcourse, a much lower degree of unsaturation, that is an iodine value ofup to 5. In this instance, unsaturated moieties of the various aminecomponents normally have up to 2 percent of unsaturated aliphatic aminecomponents as compared to 42.5 percent of such unsaturated components inthe aforesaid unhydrogenated, distilled tallow amine and itscorresponding salts.

Example 2 genated distilled tallow amine hydrochloride, i.e. sample Theprocedure of Example 1 was repeated but in this ((1); or even mixturesof hydrogenated distilled tallow instance was carried out on afull-scale plant operation amine hydrochloride and distilled cocoa aminehydroemploying seven ore portions averaging over 50,000 tons chloride inproportions outside of those of the invention, each. The procedureemployed varied, too, in the temi.e. samples (f) and (j), are utilized,is readily evidenced perature of the brine in which the ore particles ofthe in the foregoing Table II. The particularly effective persampleswere in each instance suspended. Thus, the formance of the preferredsylvite collector composition Processing of Samples and (P), as recitedcomposed of 70 percent hydrogenated tallow amine salt in Table IVappearing hereinafter, was carried out withand 30 percent saturatedcocoa amine salt is also maniin a brine temperature range of 72 F. to 89F. inclufested in the foregoing Table II. It will be seen, too, thatsive, while the processing of ore samples (q), (r), and employment ofcompositions envisioned by the present as recited in Ta le V appearinghereinafter, was invention, i.e. the flotation collection reagentsutilized in carried out within a brine temperature range of 59 F.treatment of the pulp samples (h) and (k), at a rate to 68 F. inclusive.The symbols employed in Tables of 0.13 to 0.16 pound per ton of millfeed, results in a IV and V to indicate the particular amineconditioning superior flotation recovery to that of 0.22 pound ofdisreagent used with the respective ore samples are identical tilledtallow amine hydrochloride per ton of mill feed With those recited inExample 1, i.e. A represents. distilled as manifested in the treatmentof pulp sample (1). tallow amine hydrochloride; B indicates hydrogenatedBefore hydrogenation the distilled tallow amine hydrodistilled tallowamine hydrochloride; and C symbolizes chloride of the foregoing Example1 and Table II, ernsaturated and distilled cocoa amine hydrochloride.These ployed for purposes of comparison with the compositions tablesfurther indicate the concentrations of the amine coming within thepurview of the invention, has the apreagents employed with each of theforegoing samples proximate composition recited in Table III; the aminesand the efficiency of the flotation recovery secured in reported thereinbeing employed in Example 1, as indieach instance.

TABLE IV Rate, Lbs./ Percent K20 Recovery, Sample Amine Ton ofMillPercent of N0. Used Feed K20 Equiv- Feed Concentrate Tail alent (m) A.152 22.66 55.41 1.92 94.81 (n) 2:: .118 24. 23 55. 29 1. ss 95. 54 08:: l .117 23. 33 5s. 4s 1. 73 95.38 (p) A .155 23.89 55.02 1.71 95.77

TABLE V Rate, Lbs/ Percent K20 Recovery, Sample Amine Ton of MillPercent of No. Used Feed K20 Equiv- Feed Concentrate Tail alent (q) A.150 23.05 55.90 1.48 96.12 (r) 3:: .126 22. 71 56.73 1. 57 95. 74 (s) A.146 22.87 I 56.58 2.01 94.57

cated, in admixture in the form of their hydrochloride It will beevident from the comparative studies of salts. foregoing Example 2 thatthe significant and superior TABLE III eflicacy of the cationic sylvitecollectors of the invention employed with Samples (n), (o), and (r) inthe fore- Primm, Amine of N 1 Percent going Tables IV and V is sustainedover a comparatively carbons Double BOHdS broad range of brinetemperatures.

Accordingly, it will be apparent that the present in- 14 None ventionprovides cationic mineral collectors of unex- 15 None 0.5 16 None 29. 5pected efiic1ency for effecting the recovery of sylvite from l; gag: 5-2sylvanite ores. 14 1 1:0 The criticalness of the increased efficiency inconcen- 1e Y1 is i 18 tration of sylvite values effected by the sylvitecollectors Linoleyl 18 2 1.5 of the invention as manifested in theforegoing examples is particularly evident when viewed in terms of thevast quantities of sylvanite ores mined and the criticalness of cost inthe processes involved.

Various modifications of the invention may occur, and to the extent thatsuch modifications and variations incorporate the spirit of thisinvention, they are intended to be included within the scope of theappended claims.

What is claimed is:

11. A process for effecting the froth flotation of sylvinite ore thatcomprises comminuting said ore, forming a pulp containing saidcomminuted ore suspended in a brine saturated with the constituents ofthe ore and agitating said pulp containing said sylvinite ore incomminuted condition in the presence of a cationic sylvite collectorcomposed of a mixture of 65 percent to 75 percent by weight of an acidaddition salt of hydrogenated distilled tallow amine and 35 percent to25 percent, respectively, of an acid addition salt of distilled cocoaamine, said mixture having an iodine value of less than 12.

2. A process for separating sylvite values from pulp formed of particlesof comminuted sylvinite ore suspended in a brine saturated with theconstituents of said ore that comprises subjecting said pulp to a frothflotation process employing as the cationic sylvite collector, a mixtureof 70 percent by weight of an acid addition salt of hydrogenateddistilled tallow amine and 30 percent of an acid addition salt ofdistilled cocoa amine, said mixture having an iodine value of less than12; and said mixture being employed in an amount of 0.07 to 0.16 poundper ton of said ore.

3. A process for separating sylvite values from a pulp composed of amill feed of comminuted sylvinite ore suspended in a brine saturatedwith the constituents of said ore that comprises subjecting said pulp toa froth flotation process employing as the cationic sylvite collector, amixture of acid addition salts of the primary unbranched, saturated andolefinically unsaturated aliphatic amines, caprylyl amine, capryl amine,lauryl amine, myristyl amine, palmityl amine, stearyl amine, oleylamine, and linoleyl amine in percentages by weight, re spectively, ofabout 1.5 percent, 1.8 percent, 13.5 percent, 6.0 percent, 25.1 percent,46.6 percent, 5.2 percent and 0.3 percent; said mixture having an iodinevalue of less than 12; and said mixture being employed in an amount byweight .07 to .16 pound per ton of said mill feed; said process beingconducted at ambient temperatures.

4. The process of claim 3 wherein the process is carried out at atemperature within the range of 60 F. to 90 F.

5. A froth flotation composition comprising a pulp composed ofcomminuted sylvinite ore suspended in a brine saturated with theconstituents of said ore; and admixed therewith, a cationic sylvitecollector composed of a mixture of 60 percent to 80 percent by weight ofan acid addition salt of hydrogenated tallow amine and 40 percent to 20percent, respectively, of an acid addition salt of distilled cocoaamine, said mixture having an iodine value of less than 12.

6. A forth flotation composition comprising a pulp composed ofcomminuted sylvinite ore suspended in a brine saturated with theconstituents of said ore; and admixed therewith, a cationic sylvitecollector composed of a mixture of percent to percent by weight of anacid addition salt of hydrogenated distilled tallow amine and 35 percentto 25 percent, respectively, of an acid addition salt of distilled cocoaamine, said mixture having an iodine value of less than 12.

7. A froth flotation composition comprising a pulp composed ofcomminuted sylvinite ore suspended in a brine saturated with theconstituents of said ore; and admixed therewith, a cationic sylvitecollector composed of a mixture of 70 percent by weight of an acidaddition salt of hydrogenated distilled tallow amine and 30 percent ofan acid addition salt of distilled cocoa amine, said mixture having aniodine value of less than 12; and said mixture being employed in anamount of 0.07 to 0.16 pound per ton of said ore.

8. A froth flotation composition comprising a pulp composed of acomminuted sylvinite ore suspended in a brine saturated with theconstituents of said ore; and admixed therewith, a cationic sylvitecollector composed of a mixture of acid addition salts of the primaryunbranched saturated and olefinically unsaturated aliphatic amines,caprylyl amine, capryl amine, lauryl amine, myristyl amine, palmitylamine, stearyl amine, oleyl amine, and linoleyl amine in percentages byweight, re spectively, of about 1.5 percent, 1.8 percent, 13.5 percent,6.0 percent, 25.1 percent, 46.6 percent, 5.2 percent and 0.3 percent;said mixture having an iodine value of less than 12; and said mixturebeing employed in an amount by weight of 0.07 to 0.16 pound per ton ofsaid comminuted sylvinite ore.

9. A process for separating sylvite values from pulp formed of particlesof comminuted sylvinite ore suspended in a brine saturated with theconstituents of said ore that comprises subjecting said pulp to frothflotation employing a cationic sylvite collector composed of a mixtureof 60 percent to percent by weight of an acid addition salt ofhydrogenated tallow amine and 40 percent to 20 percent, respectively, ofan acid addition salt of distilled cocoa amine, said mixture having aniodine value of less than 12.

References Cited by the Examiner UNITED STATES PATENTS 2,355,365 8/1944Cole 209166 2,689,649 9/1954 Atwood 209-466 2,695,100 11/1954 Barr209-166 2,772,775 12/1956 Atwood 209166 X OTHER REFERENCES Noller, C.R., Chem. of Org. Compds., W. B. Saunders Co., OD 253 N 65 Phila. 1955(p. 179).

HARRY B. THORNTON, Primary Examiner. R. HALPER, Assistant Examiner.

1. A PROCESS FOR EFFECTING THE FROTH FLOTATION OF SYLVINITE ORE THATCOMPRISES COMMINUTING SAID ORE, FORMING A PULP CONTAINING SAIDCOMMINUTED ORE SUSPENDED IN A BRINE SATURATED WITH THE CONSTITUENTS OFTHE ORE AND AGITATING SAID PULP CONTAINING SAID SYLVINITE ORE INCOMMINUTED CONDITION IN THE PRESENCE OF A CATIONIC SYLVITE COLLECTORCOMPOSED OF A MIXTURE OF 65 PERCENT TO 75 PERCENT BY WEIGHT OF AN ACIDADDITION SALT OF HYDROGENATED DISTILLED TALLOW AMINE AND 35 PERCENT TO25 PERCENT, RESPECTIVELY, OF AN ACID ADDITION SALT OF DISTILLED COCOAAMINE, SAID MIXTURE HAVING AN IODINE VALUE OF LESS THAN 12.